The technical field of the present invention relates to additive manufacturing, more commonly known as three dimensional printing, or “3D printing”, and to the removal of support material from objects created by 3D printing.
3D printing is popular for modeling, prototyping, tooling and production applications. The 3D printing processes build parts layer-by-layer by extruding, jetting, photo-curing, laminating or fusing materials. As parts are built some method of support is required for layers that extend beyond the profile of the previously deposited layer(s) underneath. To support such overhanging layers, the 3D printer forms sacrificial structures underneath using a support material. FIG. 1 shows a simple example, with a 3D printed part 1 atop a printer build plate 2, and support material 3 between the overhanging sides of the part and the build plate. Support material structures are constructed so as to be removable without damaging the actual part, and may be made from the same or a different composition than the part.
An improved process utilizes support materials that are soluble and eventually dissolve when placed in a bath containing a water-based mild alkaline solution. There are currently a number of commercially available cleaning bath systems designed to chemically remove soluble support material. These systems use methods that rely on various wet cleaning processes and techniques but do not remove the support material effectively. The processes used include for example spraying, mechanical agitation, ultrasonic excitation, and uncontrolled water circulation.